I think THE classic sign of a bubble is when every man, his dog and great uncle are all of a sudden investing in a particular asset.
Have you seen there are now little stalls in the shopping centres trying to get people to flog off their gold jewelry?
I remember during the dotcom >>>bubble<<<
1> if you tried to claim it was a bubble you were shouted down as if you were a hater.
2> Even school kids formed little share investment clubs and came on A current affair talking about how they were making money. Of course, they just rode the wave before the bublew popped.
3> Increases were exponential until the music stopped.
in the words of Martis... just my humble opinion :)